Flow cytometry is a technology that is used to simultaneously measure and analyze multiple physical characteristics of single particles, such as single cells. The characteristics and properties of cells that can be measured using flow cytometry include the size, granularity, internal complexity, fluorescence intensity and other features of the cells. Detectors, such as photomultiplier tubes, are used to detect forward scatter, side scatter and fluorescence to measure various properties of the cell. The characteristics and properties that are identified by flow cytometers can then be used to analyze, identify, and/or sort cells.
A typical flow cytometer uses three main systems, i.e., a fluidic system, an optical system and an electronics system. The fluidic system transports particles in a fluid stream past laser beams for illumination. The optical system includes lasers that illuminate individual particles in the fluid stream, optical filters that filter the light and photomultiplier tubes that detect fluorescence and/or scatter. The electronic system processes the analog signal generated by the photomultiplier tubes or other detectors, processes those signals in analog and/or digital form, provides identification information for the cells and generates control signals for controlling the sorting of particles.
Since flow cytometers operate at very high speeds, it is necessary for the electronics systems to also operate at very high speeds and very accurately with high resolution and high dynamic range.